Unix/Linux Go Back    


NetBSD 6.1.5 - man page for hypot (netbsd section 3)

Linux & Unix Commands - Search Man Pages
Man Page or Keyword Search:   man
Select Man Page Set:       apropos Keyword Search (sections above)


HYPOT(3)			   BSD Library Functions Manual 			 HYPOT(3)

NAME
     hypot, hypotf -- Euclidean distance and complex absolute value functions

LIBRARY
     Math Library (libm, -lm)

SYNOPSIS
     #include <math.h>

     double
     hypot(double x, double y);

     float
     hypotf(float x, float y);

DESCRIPTION
     The hypot() functions compute the sqrt(x*x+y*y) in such a way that underflow will not hap-
     pen, and overflow occurs only if the final result deserves it.

     hypot(infinity, v) = hypot(v, infinity) = +infinity for all v, including NaN.

ERRORS
     Below 0.97 ulps.  Consequently hypot(5.0, 12.0) = 13.0 exactly; in general, hypot returns an
     integer whenever an integer might be expected.

     The same cannot be said for the shorter and faster version of hypot that is provided in the
     comments in cabs.c; its error can exceed 1.2 ulps.

NOTES
     As might be expected, hypot(v, NaN) and hypot(NaN, v) are NaN for all finite v; with
     "reserved operand" in place of "NaN", the same is true on a VAX.  But programmers on
     machines other than a VAX (it has no infinity) might be surprised at first to discover that
     hypot(+-infinity, NaN) = +infinity.  This is intentional; it happens because hypot(infinity,
     v) = +infinity for all v, finite or infinite.  Hence hypot(infinity, v) is independent of v.
     Unlike the reserved operand fault on a VAX, the IEEE NaN is designed to disappear when it
     turns out to be irrelevant, as it does in hypot(infinity, NaN).

SEE ALSO
     math(3), sqrt(3)

HISTORY
     Both a hypot() function and a cabs() function appeared in Version 7 AT&T UNIX.  cabs() was
     removed from public namespace in NetBSD 5.0 to avoid conflicts with the complex function in
     C99.

BSD					February 12, 2007				      BSD
Unix & Linux Commands & Man Pages : ©2000 - 2018 Unix and Linux Forums


All times are GMT -4. The time now is 03:10 AM.